Continuous-casting arrangement comprising a reciprocating open-ended mold and a tundish

ABSTRACT

A continuous-casting arrangement comprises open-ended mold and a tundish disposed above it wherein the space between molten metal in the mold and the tundish is sealed for the purpose of pressure regulation. The invention is characterized by the fact that the mold consists of a stationary outer part that is fixed to the tundish and of an inner part facing metal in the mold with a sliding seal interposed between the inner and outer mold parts, there being means connected for oscillating the inner part within the outer part.

United States Patent Klaus Brock [72] Inventor Dusseldorf, Germany [21] Appl. No. 812,993 [22] Filed Apr. 3, 1969 [45] Patented Oct. 12, 1971 [73] Assignee Schloemann Aktiengesellschaft Dmseldort, Germany [32] Priority Apr. 8, 1968 [33] Germany [31] P 17 58 133.8

[54] CONTINUOUS-CASTING ARRANGEMENT COMPRISING A RECIPROCATING OPEN-ENDED MOLD AND A TUNDISH 3 Claims, 2 Drawing Figs.

[52] US. Cl 164/260, 164/83, 164/281 [51] Int. Cl 822d 11/00,

B22d 27/08 [50] Field of Search 164/82, 83, 260, 273, 283, 348, 281

[56] RefereneesCited UNITED STATES PATENTS 2,825,104 3/1958 Jones 164/83 X 3,414,047 12/1968 Saunders .164/283 3,482,621 12/1969 l-lalliday 164/281 1,385,595 7/1921 Van Ranst. 164/83 2,667,673 2/ 1954 Harrison... 164/283 X 3,040,396 6/1962 Hudson 164/83 X 3,370,641 2/ 1968 Greenberger 164/283 X FOREIGN PATENTS 561,968 3/1957 ltaly 164/283 Primary ExaminerR. Spencer Annear Att0meySandoe, Hopgood & Calimafde PATENTEI] DDT 1 2l97l SHEET 2 [1F 2 INVENTOR. KLAUS BROCK BY 5M W W $6M ATTORNEYS CONTINUOUS-CASTING ARRANGEMENT COMPRISING A RECIPROCATING OPEN-ENDED MOLD AND A TUNDISII The present invention relates to a continuous-casting arrangement in which molten metal flows from a tundish through a pouring tube into an open-ended mold disposed beneath the tundish and is continuously withdrawn in the form of a strand.

In order that uniform metallurgical properties may be obtained consistently in the process, the molten metal in the mold must be maintained at a constant level. This is accomplished, for example, by a system regulating the flow of metal from tundish to mold where the space between the surface of molten metal in the mold and the bottom of the tundish is sealed and maintained under the pressure of a preferably inert gas. The pressure, and hence the flow of metal into the mold, is regulated as a function of the measurements of a level-detection device.

In a prior art system of this type, sealing of the space above the molten metal is achieved by rigidly joining mold and tundish together with a gasket interposed between them. In machines where the mold oscillates in the direction of the strand axis, this arrangement is not satisfactory since the tundish bottom then executes a motion relative to the level of mo]- ten metal in the mold, with the result that the volume of the space between them is varied by the oscillation.

This produces an undesired reciprocating flow of molten metal in the pouring tube that is in synchronism with the oscillating cycle. Another disadvantage of this arrangement is that the large mass of the tundish with the molten metal which it holds participates in the oscillatory motion.

These disadvantages are overcome in another prior art design in which tundish and mold are joined through a metallic bellows. However, the short life and elaborate sealing of the bellows at the mold and at the tundish militate against the use of this arrangement. Moreover, the use of such a bellows would make it necessary to increase the distance between mold and tundish, which is undesirable.

The present invention has as its object an open-ended mold which is sealed against a tundish, in which the sealing elements are not subject to unduly rapid wear and tear and in which uncontrolled backflow of molten metal induced by the oscillation does not occur.

In accordance with the invention, this is accomplished by fabricating the mold from an outer, stationary part that is fixed to the tundish and from an inner part or sleeve that faces the strand, a sliding seal being interposed between the inner and outer mold parts, and the inner part being provided with a conventional oscillating drive.

In an advanced embodiment of the invention, the innermost sleeve which is in contact with the molten metal is provided with an oscillatory drive and the cooling jacket which surrounds said sleeve is joined to the stationary mold skirt, a sliding seal being interposed between the sleeve and the stationary part. This results in an arrangement whose components are not subject to appreciable wear. The distance between mold and tundish may be kept very small. Since only the sleeve oscillates, the volume of the space above the molten metal varies only slightly. The resultant minor pressure variations may be minimized still further by providing a communication to a large equalizing vessel.

In another advantageous embodiment of the invention, the sleeve and the cooling jacket with the associated distributors are constructed as a unit and provided with an oscillating drive, a sliding seal being interposed between the inner mold assembly and a stationary mold skirt surrounding it.

In accordance with a further characteristic of the invention, it is advantageous in multistrand casting to arrange side by side a plurality of said inner mold assemblies and to guide them in one common mold skirt. The inner mold assemblies are sealed against the skirt and provided with an oscillating drive.

Two embodiments of the invention are shown in the drawings, in which:

FIG. 1 illustrates a continuous-casting arrangement with an oscillating inner sleeve, and

FIG. 2 a continuous-casting arrangement with an oscillating inner assembly consisting of sleeve and cooling jacket.

Shown in both figures is a tundish l for accommodation of molten metal 8, said tundish being fixed to the top plate 3 of a mold, with a gasket 2 interposed between them. Plate 3 is secured to the mold skirt 4 whose underside a further plate 5 is fastened. The mold skin 4 is supported on a frame (not shown) on the casting deck of the continuous-casting machine.

A pouring tube 6 which extends into the molten metal 8 in the inner sleeve 7 is inserted in the bottom of the tundish l. A lever 11 fulcrumed on a bearing 10 and engaging an external stud 9 on the sleeve 7 is adapted to be reciprocated in the directions indicated by the arrows so as to produce an oscillatory motion.

In the arrangement shown in FIG. I, two further plates 12 and 13 are mounted between the gasket 2 and the plate 3. Plate 12 is provided with a seal 14, secured by a ring 15, whereby the space 16 above the molten-metal level is sealed against the tundish 1.

Through passages 17 provided in the plate 13, the space 16 can be connected either to a source of a pressure medium or to a vacuum (not shown), depending on whether the rate of flow is to be increased or decreased.

The sleeve 7 is surrounded by a cooling jacket I8 which is connected to the mold skirt 4 by walls 29 and 30, respectively, which form an upper and a lower annular distribution chamber 19 and 20. Cooling-water supply and discharge connections 21 and 22, respectively, connect with the distribution chambers 19 and 20. Distribution chamber 19 is sealed against the sleeve 7 by means of a seal 24 that is held by a ring 23.

Cooling water which may leak through said seal 24 is able to flowotf through passages 25 and 26 provided in the plate 3. The lower distribution chamber 20 is sealed by the seal 28, which is secured by the ring 27.

In the continuous-casting arrangement shown in FIG. 2, a cylindrical body 31 is guided in the mold skirt 4 between seals 32 and 33. Disks 34 and 35 are inserted in the ends of the cylindrical body 31, being secured on the inside to the sleeve 7 by means of supports 36 and 37.

A cooling jacket 38 is connected to the cylindrical body 31 by horizontal walls 39 and 40 which form at both ends of the cylindrical body 31 annular distribution chambers 4i and 41 that are provided with cooling-water supply and discharge passages 42 and 43. Seals 45 which are held by rings 44 are disposed in the disks 34 and 35 to provide for sealing of these distribution chambers.

What is claimed is:

l. A continuous-casting arrangement comprising an openended mold and a tundish disposed above it wherein the space between molten metal in the mold and the tundish is sealed for the purpose of pressure regulation, characterized by the fact that the mold consists of a stationary outer part that is fixed to the tundish and of an inner part facing metal in the mold, a sliding seal being interposed between the inner and outer mold parts, there being connected for oscillating the inner part with the outer part.

2. A continuous-casting arrangement as defined in claim 1, characterized by the fact that a cooling jacket surrounding the inner part is secured to the stationary mold skirt, a sliding seal being interposed between the inner part and the stationary outer part.

3. A continuous-casting arrangement as defined in claim 1, characterized by the fact that the inner part and the cooling jacket are constructed as a unit having distribution chambers therein and having means connected for oscillating said unit, a sliding seal being interposed between said unit and a skirt portion of the outer part surrounding the unit. 

1. A continuous-cAsting arrangement comprising an open-ended mold and a tundish disposed above it wherein the space between molten metal in the mold and the tundish is sealed for the purpose of pressure regulation, characterized by the fact that the mold consists of a stationary outer part that is fixed to the tundish and of an inner part facing metal in the mold, a sliding seal being interposed between the inner and outer mold parts, there being connected for oscillating the inner part with the outer part.
 2. A continuous-casting arrangement as defined in claim 1, characterized by the fact that a cooling jacket surrounding the inner part is secured to the stationary mold skirt, a sliding seal being interposed between the inner part and the stationary outer part.
 3. A continuous-casting arrangement as defined in claim 1, characterized by the fact that the inner part and the cooling jacket are constructed as a unit having distribution chambers therein and having means connected for oscillating said unit, a sliding seal being interposed between said unit and a skirt portion of the outer part surrounding the unit. 